The present invention relates to a hand labelling apparatus for imprinting and dispensing pressure-sensitive labels, comprising a housing, a print wheel which is mounted rotatably about an axis between a rest position and an operating position and on the peripheral surface of which print types are disposed in a plurality of planes adjacent each other in the axial direction, and an adjusting spindle extending parallel to said axis and connected to the print wheel, said spindle being displaceable at a side face of the print wheel between a pushed-in position and a withdrawn position and projecting outwardly through a housing wall, and with the aid of said spindle the print types disposed in the various planes are adjustable relatively to each other in such a manner that desired print types move into a printing zone at the peripheral surface of the print wheel.
Such a hand labelling apparatus is already known from U.S. Pat. No. 3,330,207. In this hand labelling apparatus the setting or adjusting spindle, with which desired print types on the print wheel can be brought into a print position, projects from the housing side wall. When carrying out an adjusting operation the adjusting spindle must be withdrawn to a greater or lesser extent depending on which digit of the imprint to be produced with the aid of the print wheel is to be changed. If after making the change the operator forgets to return the adjusting spindle to the pushed-in position there is a danger of the adjusting spindle being damaged by knocks or even breaking off. However, even if the damage is not so severe an impact on the adjusting spindle can impair the relatively complicated adjusting mechanism within the print wheel as regards its function.
The objective of the present invention is to provide a hand labelling apparatus of the type mentioned at the beginning such that there is no danger of damage to the adjusting spindle of the print wheel in operation of the apparatus.
According to the invention this objective is achieved in that the diameter of the adjusting spindle is reduced in the region which lies in the plane of the housing wall when the adjusting spindle is completely retracted, that in the housing wall at the location in which the adjusting spindle is disposed in the rest position of the print wheel an opening is provided whose internal width is greater than the non-reduced diameter of the adjusting spindle, and that adjoining the opening in the housing wall there is a slot whose path corresponds to the path which the adjusting spindle describes on rotation of the print wheel from the rest position to the operating position and whose internal width lies between the reduced and the non-reduced diameters of the adjusting spindle.
In the hand labelling apparatus according to the invention the print wheel can rotate from the operating position to the rest position only when the adjusting spindle is completely retracted. This is achieved by the particular configuration of the adjusting spindle and the opening with the adjoining slot in the housing wall. In the rest position of the print wheel the adjusting spindle projects outwardly through the opening in the housing wall and can be displaced between the retracted and withdrawn position because the internal width of the opening is greater than the non-reduced diameter of the adjusting spindle. However, rotation of the print wheel with the adjusting spindle withdrawn is not possible because the slot adjoining the opening has an internal width which is smaller than the non-reduced diameter of the adjusting spindle. Only when the adjusting spindle is completely pushed-in can the print wheel rotate from the rest position to the operating position because in this case the region of the adjusting spindle with reduced diameter lies in the plane of the housing wall and on rotation of the print wheel enters the slot. This particular configuration compels the operator after conducting a change of the label imprint to be produced with the print wheel always to bring the adjusting spindle again completely into the retracted position because otherwise actuation of the apparatus, in which rotation of the print wheel occurs, is not possible. This eliminates the danger of damage when the spindle projects.